How do you handle the ice on the back of the freezer?
The air temperature is low, the amount of water vapor which can accept is small. Excess water vapor becomes attached to water...
The higher the temperature around the air temperature in the pipe, will produce condensation in the tube. This is because the air saturated water vapor amount decreases with the decrease of air temperature.
The freezer behind the tube temperature is very low, less than 0 degrees.
